Froth flotation is a commonly employed process for physical separation of minerals from its ore. In a flotation process, the ore is crushed and wet ground to obtain a pulp. The pulp is then aerated to produce froth at the surface. A frothing agent is added to the mixture to assist in separating valuable components from the undesired portions of the mixture in subsequent flotation steps. The basic function of the frother is to produce a swarm of air bubbles, which remain sufficiently stable for the hydrophobic mineral particles to be captured by them. The hydrophobic materials are buoyed by the bubbles bringing them to float on the surface.
The hydrophobic materials -bearing froth is collected and further processed to obtain the desired products. That portion of the ore which is not carried over with the froth is usually not further processed for extraction of mineral values there from.
While a large number of compounds have foam or froth producing properties, the frothers most widely used in commercial froth flotation operations are monohydroxylated compounds such as alcohols, pine oils, cresols and alkyl ethers of polypropylene glycols as well as dihydroxylates such as polypropylene glycols. Other effective frothers used commercially are alkyl ethers of polypropylene glycol, especially the methyl ether and the polypropylene glycols. As disclosed in U.S. Ser. No. 06/923,523 and Surface chemistry of Froth floatation by S.R.Rao.
Overall, methyl isobutyl carbinol (MIBC) is the most commonly used frother. However, there have been environmental concerns with regard to MIBC's low flash-point temperature and high vaporization rate that produces an unpleasant odor in warmer climates. As stated in Froth floatation—A century of innovation.
Therefore, there is a need for an alternative process to produce frothing agents having high flash point.